This invention relates to a cyclone separator for separating particulate material, in particular seed, from an air flow, including a filter inserted between the external whirl chamber of the separator casing and its axial air outlet, said filter comprising a shell of louvred plate material, the slits of which reckoned radially outwards incline in the rotational direction of the air in the whirl chamber.
Cyclone separators of the above mentioned type are for example used in connection with suction-pressure-blowers for the conveyance of grain and seed and the louvred plate filter has for its purpose to intensify the separation of the conveyed material from the air flow due to the fact that the rotational direction of the air is so to speak reversed when passing through the slits.
When such cyclone separators are used for treating an air flow containing comparatively light materials, such as grass seed (contrary to the general cereals), it has been difficult to cause the material to fall out of the cyclone and to prevent the filter from clogging up. This tendency to block up may of course by counteracted by increasing the flow passage of the slits, but in that case a considerable quantity of the light material will follow the air through said slits and so be lost, or it will together with the air pass through the blower associated with the cyclone separator, thereby exposing said blower to wear.